United Nations population projections in 1993 were for the world population to double from the current 5.5 billion to 11 billion by 2050.
Nearly 95% of the projected rise would come from developing countries, despite successes that many Asian and Latin American countries have had in bringing down their birth rates.
Because of emigration and limited natural resources, all countries will feel the effects of growth.
Sub-Saharan Africa has the highest fertility rates, averaging more than 6 children per woman.
Zimbabwe has a particularly high birth rate with many girls giving birth to their first child in their early teens.
The Mexican government is battling huge population growth in a strongly Catholic country.
The successful lowering of birth rates in countries such as China, India, Iran, Tunisia, Egypt, and Brazil are worth noting.
The low birth rates in these countries and in Western Europe have slowed world population growth.
In Tunisia, for example, government efforts to educate women and bring them into the workforce helped lower birth rates to 1.9 % per woman.
In all of these countries success was achieved through education about family planning and availability of contraceptive devises.
China's "one child" policy has kept population growth down to the same 1.9% as in western Europe.
However, Kerala, India has been able to reduce its birth rate to the same percentage as China's without state coercion.
Western Europeans countries are experiencing a "baby bust" with extremely low birth rates in all countries except Ireland and Poland.
